This invention relates generally to the art of open-fireplace grates, and more particularly to fireplace grates in which air to be heated is circulated.
It has long been recognized that open fireplaces are relatively inefficient with some experts estimating that almost ten times more heat goes up chimneys than fireplaces throw into homes. Forced air fireplace grates have been devised to correct this situation, with some related devices being described in U.S. Pat. Nos. 3,240,206 to Shutt; 2,828,078 to Snodgrass; 1,608,745 to Holbek; 2,359,197 to Brooks; and 3,001,521 to Reilly. Further, similar grates are described in Popular Mechanics, October 1974, pages 154-175; and Dec. 1974, pages 174-176.
For a forced-air heating fireplace grate to be most beneficial it should possess the following characteristics:
1. It should be an efficient log holder;
2. It should be easily installable in a large variety of sizes and shapes of fireplaces;
3. It should be uncomplicated and inexpensive to manufacture;
4. The duct work thereof should form an integral grate so that as few as possible additional support members are required;
5. The inlet and outlet transfer ducts thereof for guiding air to and from the grate should be adjustable so that they can be placed on either side of the fireplace and so that they can be easily made to fit fireplaces of various depths;
6. It should be an efficient heat exchanger so that as much duct work as possible is utilized for transferring heat from hot coals to flowing air;
7. It should be designed so that it allows efficient fire-supporting ventilation but yet holds hot ashes and coals in contact with duct work to optimize heat exchange properties.
None of the forced-air heating fireplace grates described in the above mentioned prior art patents and publications provides all of these characteristics. Thus, it is an object of this invention to provide a forced-air heating fireplace grate which has these characteristics.